Various solutions have been presented in the past for evacuating people from buildings, airplanes, ships and oil rigs. When the height is given and constant, one set of conditions are given, but when the height varies the problems become more difficult. Varying height is especially present under maritime emergency conditions, e.g. due to high waves and/or because a ship has a list, i.e. is tilting to one side because of a displaced cargo or due to a hole in one side where water is flooding in. Maritime emergencies often happen during stormy weather which is a factor that increases the problem of varying height. In one known solution there is a slide which extends from the high evacuation point and downwards in a 30-45 degree angle away from the ship to the sea.
The company VIKING LIFE-SAVING EQUIPMENT of Esbjerg, Denmark, has marketed maritime systems adapted for evacuation where most of the descent is practically vertical. Such systems comprise a chute having a succession of linked, rigid and spaced apart steel rings which are connected by elastic cords attached to the rings. The elastic cords and rings are arranged to allow longitudinal stretching as well as contraction. The chute also has an elastic tunnel-like device arranged and held inside the succession of rings. The tunnel-like device is adapted to slow a rate of descent of a falling person who is being evacuated through the tunnel-like device. Each elastic cord extends vertically from the top to the bottom of the chute when the chute is in use and is launched from a high evacuation position and allowed to extend freely downwards. The long elastic cords are attached to each ring with a bracket and extend in parallel, vertical courses of direction, each being parallel to a longitudinal axis of the chute. Normally the lower end of the chute is anchored at a floating platform or life raft. Due to the elastic cords, the chute is able to stretch as well as contract to compensate for varying height caused by waves. This allows people to escape through the chute even when the length of the chute changes.
Escape or rescue devices are also known from WO 84/02658 and U.S. Pat. No. 3,973,644. WO 84/02658 discloses a tunnel-like escape device comprising a stocking of canvas material or similar material. The stocking, which is made of netting permitting the passage of wind, is with axial intervals provided with an annular reinforcing element for stretching out the stocking. The stocking is connected to two or more axially extending lines which are connected to the reinforcing elements and to each reinforcing element on diametrically opposite sides thereof. However, since rigid lines are used to connect the reinforcing elements, such a device is unsuitable for use where the vertical escape height is varying. U.S. Pat. No. 3,973,644 discloses a rescue apparatus for enabling persons to escape safely from burning buildings, for instance, and comprises a flexible tubular device which is elastic only in the transverse and circumferential direction to slow the rate of descent of a body falling through the tubular device, various means being provided for fixing the open upper end of the tubular device to the elevated point when the person is to be rescued through the lower open end of the device. Furthermore, such an apparatus is unsuitable for compensating for varying height.
Over the years it seems that storms are becoming harsher. Also, ships and liners are becoming larger and larger. This combination calls for an improvement of escape systems in order to increase safety in such conditions.